Read through the "Line Length" part of the Python Style Guide. A link to it has been added to the bottom of the Programming Style section of this page. You can also get to it from the "External Links" section of this web page.

Introduction

Welcome to CS21! This course will introduce fundamental ideas in computer science while also
teaching you how to write computer programs. We will study algorithms for
solving problems and implement solutions in the Python programming language. Python is an
interpreted language that is known for its ease of use. We also introduce
object-oriented programming and data structures. A deeper coverage of these
topics will be presented in CS35.

This course is appropriate for all students who want to learn how to write
computer programs and think like computer scientists. It is the usual first
course for computer science majors and minors. Students with advanced placement
credit or extensive programming experience should place out of this course and
instead begin with CS35. If you have no prior computer science or programming experience, this course is designed for you.

Goals for the Course

By the end of the course, we hope that you will have developed the
following skills:

Given a program, be able to simulate on paper how a computer would
execute the program, and show the results that would be produced.

Given a problem, be able to design a clear, concise, and
correct pseudo code algorithm to solve it.

Given a pseudo code algorithm, be able to successfully implement it in
Python.

Be able to use top-down design to sub-divide a large problem into
reasonably-sized modular sub-problems.

Given several algorithms for solving the same problem, be able
to analyze which algorithm would be more efficient in terms of running
time.

Develop debugging and unit testing skills. Consistently use
these skills while implementing programs.

Learn to work as part of a team to solve problems starting from
design and continuing through to implementation.

Study sessions

Several student mentors will assist me in
class and run study sessions in the main CS lab (Science Center 240) on
the following evenings:

Day

Time

Location

Sunday

7-9pm

Sci Center 240

Wednesday

7-9pm

Sci Center 240

You are invited – and encouraged – to participate in these study
sessions to prepare for quizzes, to discuss programming concepts, and
to get friendly assistance in working on homework assignments. Our CS
mentoring team is dedicated to helping students, who have no prior
knowledge of computer science, learn to program in Python while
keeping their senses of humor intact. As an added bonus, free food
will be provided at the sessions.

Weekly Lab Office Hours

CS21 faculty will staff part of our office hours in the robot lab (252 Science Center). Any CS21 student is welcome to attend any session.

Grading

Grades will be weighted as follows:

40%

Homework assignments

30%

Quizzes

5%

Class Participation

25%

Final Exam

Homework policy

Programming assignments will typically be assigned in class at the
beginning of the week and will be due before midnight the following
Tuesday night. You are strongly encouraged to start early and to
attend the study sessions for extra practice.

You will submit you assignments electronically using the
handin21 program. You may submit your assignment multiple
times, but each submission overwrites the previous one and only the
final submission will be graded. Late assignments will not be accepted
except in extreme situations and only if you contact me before the
deadline. Even if you do not fully complete an assignment, you may
submit what you have done to receive partial credit.

How to Succeed in CS21

Read the material before you come to class.
Don't worry about total comprehension, but at least get a feel for
what we will be covering that week. If you have some understanding of
the material coming into class, it will be easier for you to ask
questions during class, rather than later when help may not be
available. Additionally, we often do lab exercises during class. This
is an important part of the learning process, as these exercises give
you immediate experience with the material we are covering. If you
read the book before you come to class, you'll be able to complete
these exercises more easily.

Ask questions if you don't understand.
This means both during class and while doing your homework. This class
continually builds on previous material, so if you don't understand
something one week, it will continue to be a problem the next week,
and the week after that, and so on. If you need help, ask your classmates,
attend the study sessions, come talk with me during my office hours, or
email me your question.

Start the homework assignments early.
I realize this one is not always easy to do, but if you can get in the
habit of doing this, you will be much better off. If you get
stuck early (i.e., not two hours before it is due), there will be time
to look for help. In addition, if you start early enough, you can
take a break, go do something else, and come back later. I find I
always have at least a few new ideas when I come back to a problem
after a break. If you wait until the last minute, you can't do this.

Practice, practice, practice. The only effective way to
learn the material and pass the quizes and exams is to consistently
do the homework. Finish all of the assigned programs (and do some extras,
for fun!). Even if you don't get them done on time, they will still
help you learn the material.

Seek help early and often. Because course material builds
on previous material, it is essential to your success in this class
that you keep up with the course material. If you are having difficulty
with a programming assignment, if you didn't follow something covered
in lecture, if you feel you need some extra help understanding or
practicing some of the course material, or if you just want to discuss
something from a lecture, an assignment, or the text, please come to
my office hours.

Attend CS21 Study Sessions. The CS21 Student Mentors (Ninjas)
hold evening study sessions each week.
You are encouraged to participate in these sessions. The Ninjas
will help you prepare for quizzes, will provide additional instruction
in programming concepts, and will provide friendly assistance on
your homework assignments.

Work with a partner. Several of the assigments will optionally allow you to work with a partner. This is highly recommended. Working in groups can help you progress further through the assignment more quickly. Partners can often catch silly coding mistakes that may leave you frustrated for hours if working alone. Explaining concepts and ideas to a partner is a great way to help you learn the material and clarify your thinking. If you are interested in working with a partner but do not know who to ask, contact me and I can try to pair you up with a compatible student.

Programming Style

Programming is not a dry mechanical process, but a form of art. Well
written code has an aesthetic appeal while poor form can make other
programmers and instructors cringe. Programming assignments will be
graded based on style and correctness. Good programming practices
usually include many of the following principles:

Academic Integrity

Academic honesty is required in all work you submit to be
graded. You may not submit work done with (or by) someone
else. You may not examine or use work done by others to
complete your own work. You may discuss assignment
specifications and requirements with others in the class to
be sure you understand the problem. In addition, you are
allowed to work with others to help learn the course
material. However, with the exception of the student
mentors and your partner on group assignments, you may not work
with others on your assignments.

All code you submit must be your own with the following
permissible exceptions: code distributed in class, code
found in the course text book, and code worked on with an
partner. In these cases, you should always include
detailed comments that indicates on which parts of the
assignment you received help, and what your sources were.

"It is the opinion of the faculty that for an intentional
first offense, failure in the course is normally appropriate.
Suspension for a semester or deprivation of the degree in that
year may also be appropriate when warranted by the seriousness
of the offense." - Swarthmore College Bulletin (2008-2009, Section 7.1.2)

Please see me if there are any questions about what is permissible.

External Links

Links that are related to the course may be posted here. If you have suggestions for links, let me know.